Mechanical dishwasher



Aug. 13, 1929. w. R. WALKER MECHANICAL DIsHwAsHER 5 Sheets-Sheet 1 FiledMarch 29, 1927 Aug. 13, 1929. w. R. WALKER 1,724,383

MECHANICAL DIsHwAsHER v Filed March 29,V 1927 s sheets-sheet 2 MNV /vraMm; f MM( l Aug. 13, 1929. w, R, WALKER 1,724,383

MECHANICAL DISHWASHER Filed March 29, 1927 5 Sheets-Sheet 3 Mf/m Y MM s,

Patent Aug.. i3, E99.'

application met marca ae, ma?. serial ro. iraasa plane of 3 3, Figrlhisinvention relates to a mechanical dishwasher involving the use of' a vator tub for receiving suitable open-work dishsupporting trays commonlyused'- in washers of this character together with a washing luid whichis impelled cirurnferentially and upwardly with a whirling motionthrough the open work trays and against the dishes therein by means of arotary 1mpeller located within the vat near the bottom thereof andadapted to be driven by an electric motor or equivalent device. .g

In machines of this type one of the objects is to regulate the volume ofwater operated upon so as to conserve the washing uld and power re uiredfor circulatin the saine without sacri cing the washing e ciency of themachine and one of the specic purposes of the present machine is tocarry .forward this main object to a more practical and economicaldegree than has heretofore been practiced.

Another object is to enable the entire vat to be constructed ofreasonably light sheet k:metal and to provide means whereby the gearcase and motor may be supported upon the underside of the vat withoutoverstrain-- ing any of the sheet metal parts to which they areconnected.

A' further object is to rovide means for regulating the volume o waterin the vat and for indicating the level thereof and also to providemeans whereby thewater may be drained from the vat and from the liquid`level indicator.

Another object is to provide means for supplying water to the interiorof the vat -or washing and rinsing purposes and to locate the controlsfor the inflow and out- How of the water to and from the vat withinconvenient reaching distance of the operator and preferably at one sideof the vat near the top thereof where they are more or less protectedfrom accidental operation by the top section of the vat.

Other objects and uses relating to specific parts of the machine will bebrought out in the following description.

In the drawings Figure 1 is a top plan partly broken away, of amechanical dishwasher embodying the various features of my invention.

-Figure 2 is a front elevation of the same, portions of thev legs beingbroken away.

Figure 3 is an enlarged vertical sectional view taken in the ure l.

.Figure 4 is an enlarged detail vsectional view, partly broken away,taken on line .4r-4, Figure 2.

As illustrated, this machine comprises a substantially cylindrical sheetmetal tub or vat lhaving a circular sheet metal bottom section -2-` anda sheet metal top 'lhe lower and upper ends of the cylindrical section-lare parallel and Aat right angles to the axis thereof, the lower endof said section being returned inwardly and upwardly for a shortdistance to form an annular groove for receiving the marginal edge ofthe bottom section -2-. v

This bottom section 2- isV provided with inner and outer frusto-comcalportions -2- and -2- concentric with the axis of the cylindrical section,--land arranged with their apices facing in opposite directions orupwardly and downwardly respectively, the` central portion -2- havingits apex extended above the level of the outer marginal edge and itsouter edges integrally united to the inner edges of the outer portion toform an annular trough 4+ at the junctions of the `two portions -2- and2- for the reception and retention of a limited quantity of the washingfluid.

The marginal edge of the bottom section 2- is provided with adown-turned flange 5 seated in the annular groove in the lower end ofthe cylindrical section -1- wherein it is secured by any suitablefastening means such as screws 54- to form a liquid tight joint.

The central truste-conical portion 2'- is provided with a centralopening in its apex co-axal with the am's ofy the sect'non -lforreceiving the upper reduced externally threaded end of an upwardlytapered shell of the case -6- hav an annular Bange V-7- adapted to abutagainst the lower face of the walls of said opening, the reduced upperthreaded end of said case being engaged by a cap nut -8- which alsoengages the upper face ofthe apex of the portion -2- to .firmly clampthe case sec` tion -6- to the apex of the bottom section 2- as shownmore clearly in Figure 3.

The case section 6- is hollow and extends downwardly'some distance belowthe apex of the bottom section -2- for receiving and partiallysupporting the driving means'l'ffongt additio -9-is arran ed concentricwith the axis of. the cylindrical section -1- to extend downwardly fromthe underside of the central frusto-conical portion -2- of the bottom-2- with its apex facing downwardly and its marginal edges secured byslot welding or otherwise to the central frusto-conical portion -2- nearIits junction with the outer frusto-conical portion 2- as shown inFigure 2.

The section 9 is therefore co-axial with the axis of the cylindricalsection 1 and is provided in its apex with a vertical opening to. allowthe case section to passtherethroug The section -6- is provided with anannular flange lO- bolted or otherwise firmly secured to the undersideof the apex of the section -9- which, being braced against the centralfrusto-conical portion -2- yof the bottom -2- of the vat, serves also tobrace the section 6 against lateral vibrator movement and assists insupporting sai section I--6- and -parts carried thereby in operativeposition against vertical movement.

The bottom of the trough 4 is provided with an. outlet passage --l1-- ata lower level *than the remaining portions of said bottom which inclinesdownwardly and circumferentially from a point in the troughdiametrically opposite to said outlet so that all of the water in theltrough may be drained off at the outlet when desired.

ali-,.{fruto-efonical The top section -3- of the vat is pref-y erablyrectangular in top plan and of greater width and depth from side to sideand from frontvto rear than the diameter of the cylindrical section.-1-- and preferably 4consists offa sheet metal plate having the centralportionofits main body open and depressed to form ai circular flange-l2, the inner end of which is reduced to about the diameter of theinterior of the cylindrical section thereof,the 'portion of the flangejust above A the-lower reduced end being increased in diameter t o forman annular shoulder at -'-13- ,which `1s adapted to rest. upon the upperedgeof" the cylindrical section -1 to hold In like manner anotheropen-work basket or tray may be supported upon the marginal he'=1rr`ipeller presently described. section the upper edge The opposite sidesand front of the top section -3- are provided with down-turned flanges-14- extending preferably below of the cylindrical section rear edge ofthe top section -3- is bent upwardly to form a back portion l5 adapt-edto finish against a wall of the room but mainly to form a spatterboardto prevent splashing of water at the rear of the tub.

.A suitable cover -16, Figure 1, is supported in the open upper end ofthe 'tub section -3- to prevent escape of the washing fluid through thetop of the vat during the washing operation.

Water Ze'veZ c'orttv'oZ mul indicator.

A water supply pipe l"`,Y leading from any available source of watersupply, extends from the back forwardly beneath the horizontal portionof the top -3- with one of the side flanges -l4 and between said sidefiange and the periphery o f the adjacent portion of the cylindricalsec- -1- while the parallel tion -1- to a point near` the front cornerof the top where it is connected to the upper end of an upper valve case-18- having its lower end connected by an elbow extension -19- toanvinlet nozzle -20- in the adjacent side ofthe cylindrical section -1-for supplying water or other washing fluid to therinterior of the vat.

The nozzle -20- is firmly secured in an opening in the upright portionof the cylindrical section -1- intermediate its lower and upper end toform a water-tight joint therewith and also to allow the inflowvingwater to be used for rinsing purposes when desired.-

being provided with any suitable valve operable `at will through themedium of a handle 21 for controlling the flow of water into the vat.

The valve' -18- and certain parts` of other controls are furthershielded and partially inclosedin a supplemental housing or shield-plateQ2- having the upper end of its front portion offset forwardly andbolted or otherwise secured to the front fiange -14- of the top section--3- as shown in Figure 4.

The lower end of the plate *22- is offset rearwardly and then upwardlyto form a horizontal shelf -22 and a rear upright .p

flange -'22- for purposes presently described, the horizontal portion-22- being provided with a vertical opening therethrough for receivingthe upper end of the elbow extension *19- of the pipe.

The valve case 18- is preferably located between the front and rearupright portions of the shield or housing Q- and just above the bottomportion 2:2- but the stem of its valve extends through an opening in thefront upright portion of said housing and carries at its front theoperating handle 2lwhich is conveniently Vaccessible to the operatorwhen in a standing position.

lt will be noted that the handle 21 is also directly beneath thehorizontal portion of one corner of the top -3 and at the rear of thevertical plane of the front Harige -l4- whichenables the operator towork close to the 4front of the machine without liability ofaccidentally operating the valve handle -21- and also serves toprotectthe other manually operated controls on said plate against contact, withexternal objects from above.

'llhat is, the upright portion of the shield plate 2:2- is positionedsome distance to the rear of the vertical plate o the front flange *14-of the top4 section 3- and constitutes what may be termed an instrumentboard for receiving and supporting the valve handle -21- and othercontrolling handles presently described. The means for controlling andindicating the level of the washing fluid in the vat or tub -lcomprisesan upright shell or casing -23- located directly below the horizontalportion of one corner of the top section -3- at which the valve case 18-is positioned and in a plane some distance below said valve at about thelevel of the bottom -2- of the vat, said casing -23- being provided withan inlet nipple H24- in a plane below the outlet -llof said vat andoperativeley connected to said outlet by a conduit -25 which serves thedouble purpose of a drainage outlet and also ar a part of thelevel-regulating means.

The lower portion of the casing -23- is divided by an upright partition26- into separate upright compartments 27- and -28-, said partitionbeing extended from side to side of the casing ,-23- and terminating atits upper end below the level ofthe gland -8- but above the level ofthebottom of the trough 4 to form an overflow passage -29- from the chamber-27- to the chamber 2S- for limiting the volume of water in the vat tobe acted upon by the impeller.` r v This partition 26- is provided withan opening 30- which, together with the inlet -24- are located in aplane some diswater supply tance below the overflow passage 529- or vtop of the partition -26- and the outlet -1l-, said casing -23- beingalso provided with a drainage outlet conduit 3lat the same level as orbelow the opening -30- to allow the water to be entirely drained fromthe vat through its outlet -11- when desired.

A tubular bushing -32- is tightly fitted in the opening 30- to form a.seat for a butterfly valve -33- which is hinged at -34- to the top ofthe bushing -32- and is operatively connected to the lower end of anupright rod -35-.

The upper end of this rod 35- is connected to a crank arm 3G- on therear end of a horizontal shaft- -37- which is journaled in suitablebearings in the front and rear upright portions of the shield plate 22-and has its front end provided with a handle -38- in front of the shieldplate or instrument board to be operated at will for opening and closingthe valve 33-- A retract-ing spring 39- is operatively connected to thecrank arm 36- to yieldingly hold the valve 33 and its operating partsin'a closed position the valve being hinged in such manner as toautomatically close the direct passage for the water from the inlet -24-to the drainage pipe 31-.

A float -40'- is mounted for vertical movement in the chamber 27- and isadapted to normally rest upon suitable lugs 41*, Figure 4, in a planebelow the overflow passage -29- when the water level in thetub is belowthe level of the over- OWa On the other hand, when the valve 33 isclosed and the water level in the cham-` ber -27- rises to or above thelevel of the overflow passage--2$) the float --40- will be automaticallylifted by said rising water.

The float lO- is provided with an upwardly extending stem -42- havingits upper end made of conducting material to constitute a movableelectric switch member adapted to make contact with-a pair of terminals43- of an electric circuit 411- which derives current from an externalcircuit 45- through the medium of a stepdown transformer -46 l A bell orequivalent signal *47- is connected in the circuit 44- to be operatedwhen said circuit is closed by contact of the float rod 42- with theterminals 4S- These terminals are mounted upon an insulating base 48-which is supported upon the lower horizontal portion -22- of theinstrument board *22 as shown in Figure 4 and through which the rod 42-is adapted to extend. j

YWhen water is being supplied tothe interior of the vat by the openingot the valve -l8`- the drainage valve 33 will be closed thus permittingthe water to rise in the chamber 27- thereby lifting the float -40- andcausing the upper end of its tively connectcd to any suitable waste pipenot shown.

As soon as the signal 47- is operated the valve -18- in the supply pipewill. be

. closed by the operator through themedium On the other hand, when it isdesired to drain the water from the vat the valve -33- will be opened byproper adjustment of its operating member -38- thus permitting the waterto pass through the opening -30- into the lower end of the chamber -28-and thence outwardly through .the drainage pipe Impeller.

The means for circulating the washing fluid circumferentially andupwardly with a whirling motion comprises in this instance a horizontalelectric motor -49- mounted upon the bottom section -2- of the vat -land casing t3- and having its armature shaft operatively connected bygearshaft -51- within the case -6-.

The lower end of the upright shaft -6- in the lower end' of the case -6,the

upper end of said shaft being journaled iny vertically alined openingsrin the upper end of said case and nut -8- to extend some distance abovesaid nut.I

A collar 5S- of angular cross section is secured to the upper end of theshaft -51- directly over the nut -8- for receiving the hub -54- of arotary impeller That is, the hub -54- is closed at the top but isprovided with a socket extending upwardly 4fromits, lower end and ofangular cross section corresponding to the cross sec-- tional form ofthe collar -53-4- whereby the impeller maybe placed upon and removedfrom the collar -53 by vertical sliding movement, the angular form ofthe collar and socket serving as spline connections between the shaftand impeller for transmitting rotary motion from thel shaft to theimpeller.

This impeller is provided with diametrically'opposite downwardlydiverging arms -,-56 corresponding to the incline of the central coneportion -2- of the bottom 2- of the vat and adapted to travel in closeproximity thereto.v

The outer ends of these arms -56- are provided with impeller blades -57-which are preferably inclined downwardly in the direction of rotationand are -also arranged somewhat tangential to opposite sides of the hubfor circulating the water circumferentially and at the same timethrowing it upwardly with a morevor less retarded centrifugal motion andwith suflicient force to carry the water through the open-workdishsupporting trays and against the dishes therein with a glancingimpact against the dishes.v c

The impeller blades -57- conform somewhatclosely to the transversecontour of the bottom of the trough 4fand travel in close proximitythereto. V

lllhe outer end of the motor +49- is partially supported by a strap -58which is secured to the adjacent portion of the marginal edge-of the vatby one or more of the bolts The inner end of the motor case -49- issecured directly to and supported by the case 6 which, as previouslydescribed, is braced against lateral or vertical movement of its ownconical form and also by the conical brace plate -9 on ,the underside ofthe conical portion -2- of the bottom -2- of the vat thus affording asimple and convenient means for supporting a motor and-parts driventhereby against vibra- Y tion. f

The motor -47 may be connected in any well-known manner to a source ofcurrent supply not necessary to herein illustrate or describe exceptthat the operating member as 59- of the motor-controlling switch may bemounted directly upon the instrument board -22- adjacent the other.manually-operated controls -21- and -38- thus permitting all of thecontrols to be .adjusted by the operator while standing in one positionas, for example, at the front of the machine, all of saidmanually-operated controls being located at the rear ofthe verticalplane of the front Harige -14- for purpose hereinbefore described.

Operation;

to close the bell circuit across the terminals Y -43- for ringing .thebell which indicates The valve -33- may then be opened by yits operatingmember 38- to allow the water to drain oit' from the trough -A- throughthe drainage 'pipe 3lafter which the valve 33- Inay be again closed andthe valve l8- re-opened to introduce rinsing water into the vat, itbeing understood that the valve 18 isto be closed as soon as the alarm-47- is operated.

This rinsing water may be circulated in the manner previously describedby the rotation of the impeller -55- to rinse 4the disheg in the trayswithin the vat, either While the valve -18- is opened or after it isclosed. I

Following this rinsing operation the valve *33* may be again opened todrain oit' the rinsing water from the vat.

The mechanism described is particularly simple and efiicient fordish-washing purposes but it is evident that various changes may be madein the detail construction withoutdeparting from the spirit of thisinvention.

What claim isz- 1. n a mechanical dishwasher, a vat having its bottomformed of an inner frustoconical portion and a surrounding invertedfrusto-conical portion united to form an annular trough for the washingfluid. means for limitingthe quantity of fluid in the trough to thelevel below7 the apex of the,

inner conical bottom portion and a rotary impeller having portionsthereof movable in said trough about the axis thereof.

2. n a mechanical dishwasher, a vat having its' bottom provided with anannular trough for the washing fluid approximately midway between theperiphery and the axis of said vat, and a rotary impeller havingportions thereof movable in said trough' about said axis.

3. A mechanical dishwasher as in claim 2 in which means is provided forlimiting the amount of fluid in said trough to a level below the portionof said bottom adjacent the axis of the vat.

4. A mechanical dishwasher as in claim l in which aconical reinforcingsection has its -larger end secured to the underside of the innerconical portion of the bottom of the vat co-axial therewith and itssmaller end extended downwardly from the apex of the inner conicalportion.

5. In a mechanical dishwasher, a vat having a central conical bottomportion arranged with its apex uppermost and provided with an openingtherethrough, a' gear case having its upper end secured in said openingto form a watertight joint therewith, an upright shaft extending throughan opening in the upper end of the gear case A and into the interior ofthe vat, an impeller operatively mounted on the upper end of the shaftwithin said vat to rotate with the shaft, a motor attached to one sideof the gea-r case and having its armature shaft extending through saidside and gearing withinthe case for transmitting rotary motion from. thearmature shaft to the upright shaft.

6. A mechanical dishwasher as in claim 5 in which an invertedfrusto-conical reinforcing section has its apex secured to theintermediate portion of the gear case and its larger end secured to thebottom of the vat for bracing said gear case against vibratory movement.

7. In a mechanical dishwasher, a vat having its bottom provided with anupwardly projecting frusto-conical portion and an annular troughsurrounding the base of said frusto-conical portion, said trough havingan outlet, a conduit connected to the outlet and provided with anoverflow above the level of the outlet and below the level of the apexof said frusto-conical portion for regulating the amount of waterretained in the vat, and a rotary impeller having portions thereofmovable in the trough for circulating 'the fluid circumferentially andupwardly.

8. In a mechanical dishwasher, a vat having its bottom provided with anupwardly projecting frusto-conical portion and an an- ,cular troughsurrounding the base of said portion, a conduit connected to the troughand provided with an overflow passage above the level of the trough andin a plane below the apex of said frusto-conical portion, a

ioat in the conduit actuated by the rise of water therein to the levelof the overflow, a signal and means actuated by the float forcausing'the operation the time the water in the conduit reaches thelevel of the overflow.

9. In a mechanical dishwasher, a vat for receiving the washing Huid anddishes having its bottom provided with an annular trough substantiallymidway between its axis and periphery and concentric with said axls, anupright rotary shaft extending through a central opening in the bottomof the vat, a rotary impeller mounted on the upper end of the within thetrough, and means for limiting the amount of fluid in said trough to alevel of the signal at about shaft to rotate therewith I bolow tho shaftoponing in tho bottom .of

the `vat.

10. In a meehanleal dishwasher, a vat haw ing its bottom provided withan upwardly 5 tapered central portion'- andan upwardly Haring outerportion united tok the base of the central portion to form an annulartrough, an impeller rotatable in said trough, driving means for theimpeller, a supportin `10 member for the driving `means flangedagainst-the underside of the apex of the central tapered portion, and aclamping member engaging the upper side of said apex and in screwengagement with the adjacent portion of the first-named member, oney ofsaid members being extended through an opening in saidfapex. l

In witness whereof I have hereuntoset my hand this 14th day ofy March,1927.

- WILLARD R.'WALKER.

